Input devices provide a user the ability to interact with a computing device. Typical input devices can include keyboards, computer mice, styluses, remote controls or other similar forms. Input devices in the form a computer mouse provide a user interacting with the computing device the ability to perform certain activities, including navigation, cursor control, and selection functions.
A common form of computer mouse is an optical mouse. Typical optical mice function by using a light-emitting diode to detect the movement of the optkical mouse relative to a surface (e.g., a mouse pad, a desk or a table). Optical mice operate by using a sensor or camera that takes successive images of the surface upon which the optical mouse is being moved upon. Based on an overlap of successive images, the optical mouse detects the offset between the successive images which represents the distance that the optical mouse has moved relative to the surface.
One problem that exists with current optical mice is that there is an upper limit on how fast the user can move the optical mouse. Some users may require a high-performance computer mouse that is capable of detecting fast movements by the user. Some of these users may require the high-performance computer mouse for a computer game that requires the user to make fast movements using the computer mouse. If the user moves their optical mouse at a speed faster than the upper limit, loss of tracking can occur where the location of the mouse and associated cursor are lost. In such cases, successive images produced by the sensor or camera may not have sufficient overlap to determine an offset. As a result, the optical sensor may lose track of the location of the optical mouse and produce unreliable displacement and location data. This can cause a cursor displayed on a monitor or display to stop (e.g., freeze) or jump around to random positions in any direction as the optical sensor attempts to correlate any data it receives resulting in spurious correlations.
This loss of tracking can result in a negative user experience as the user is limited in the functionality and range of motion that may be conducted by the optical mouse. For example, the user may not be able to swipe their mouse quickly while engaged in a computer game without the mouse losing track of its displacement.
In previous solutions, in order to increase the upper speed limit of an optical mouse, the frame rate of the imaging sensor was increased. However, a higher frame rates is accomplished by shorter exposure times and less illumination. To compensate for reduced illumination, a brighter light source or LED and/or more sensitive imaging sensor was required. Increasing the brightness of the LED required higher power consumption and as the power consumption of the optical mouse increased, it made it difficult to design an optical mouse that would perform at high speeds and still be wireless. Being wired to a host system limits the usability of the optical mouse to the target group of users as wired computer mice limit the freedom of movement that may be required for computer gaming.
Moreover, the brightness of LED cannot be increased too much due to multiple concerns about power consumption of wireless mice, heat generation, current draw in the wired mice, increased circuit complexity of the LED drivers, etc. In addition, if the mice are based on laser LED technology due to concerns for eye safety, the brightness of the laser cannot exceed specific standards. Using a more sensitive imaging sensor also has its drawbacks as the cost is higher and there are theoretical limits on the sensitivity of the sensor related to the number of photons absorbed by each pixel during the exposure time.
Based on the foregoing, there is a need in the art for improved methods and systems for input devices that provide greater functionality and better user experience.